diff --git a/nixosModules/clanCore/metadata.nix b/nixosModules/clanCore/metadata.nix
index 7e016dce0..5e1531250 100644
--- a/nixosModules/clanCore/metadata.nix
+++ b/nixosModules/clanCore/metadata.nix
@@ -107,8 +107,7 @@ in
             readOnly = true;
           };
           tld = lib.mkOption {
-            default = "clan";
-            type = lib.types.str;
+            type = types.strMatching "[a-z]+";
             description = ''
               the TLD for the clan
             '';